So I’ve been thinking of ways to lower my motors’ KV for a number of reasons. Firstly, the potential benefits:
Decreased top speed (mine is actually too high for me, I don’t think I’ve ever even used the top half of my throttle)
Decreased current draw - this should also cause an increase in range (?)
Better startup torque/amp (as a direct result of lower current draw)
I don’t want to buy new motors, and I’d like to avoid re-winding my phases, so what I’d like to do is change my motor phase terminations from Delta configuration:
(shitty MSPaint drawings for your viewing pleasure)
This change should result in a 1.7x lower KV value in the motor, thus incurring all the benefits stated above.
My question is, will this change have any issues with my ESC (Unity)? My guess is that it’ll still be completely compatible, but I want to check before I do it.
I find some aspects of bldc’s to be both fascinating and completely mind-boggling - like how someone figured out that Delta terminations have 1.7x the KV of Wye terminations. I’d be very intrigued to see why that is but everything I’ve found treats it as just a given.
well when you change from delta to wye, your resistance will triple, which means your conductance will be 1/3 or 0.3333… and the change factor of your kv will be the square root of 0.3333 or 0.5773x
It doesn’t look like they’re soldered at all besides the bullet connections, so it should be as simple as removing the bullets, un-twisting the remaining wire, and cross-referencing with a winding diagram.
I’m an electronics noob, but is it possible to have all 6 wires come out of a motor and change the termination on the fly with relays, for a pseudo 2-speed “gearbox”?
yea a switch to wye or delta can be made out of the motor but I think the esc would ideally or maybe necessarily need to have both variables in the programming and be able to switch as well
it is possible to convert delta to wye without opening the motor connecting the individual multistrands in series outside of the motor from phase to phase I hear. never done it
Updates!
I’ve gotten started on the conversion - popped the motors open and started rearranging the wires for wye termination. I’ve just gotta remove the enamel on the wires and do a lot of continuity checks before I solder everything up and insulate. Last thing I want is a short
I should be able to finish up and make a post some time tomorrow!
Removing the stator from the frame proved to be an incredibly difficult task, so I opted to not do that and just thread the wires around different parts of the frame to make them easier to manage.
Those things were glued together incredibly well.
